Discovery of Fusarium pseudograminearum Causing Crown Rot of Winter Wheat in Xinjiang Uygur Autonomous Region, China.

Fusarium pseudograminearum is an important plant pathogen that invades many crops (Zhang et al. 2018). Since it was first discovered in Australia in 1951, F. pseudograminearum has been reported in many countries and regions and caused huge economic losses (Burgess et al. 2001). In 2012, crown rot of wheat caused by F. pseudograminearum was discovered for the first time in Henan Province, China (Li et al. 2012). Wheat (Triticum aestivum L.) is one of the most important food crops in Xinjiang Uygur Autonomous Region (XUAR), with 1.07 million hectares cultivated in 2020. In June 2023, a survey of crown rot disease was carried out in winter wheat cv. Xindong 20 in Hotan area, XUAR, China (80.148907°E, 37.051474°N). About 5% of wheat plants showed symptoms of crown rot such as browning of the stem base and white head. The disease was observed in 85% of wheat fields. In order to identify the pathogens, 36 pieces of diseased stem basal tissue, 0.5 cm in length, were collected and sterilized with 75% alcohol for 30s and 5% NaOCl solution for 2 min, then rinsed three times with sterile water and placed on potato dextrose agar (PDA) medium at 25°C. A total of 27 isolates with consistent morphological characteristics were obtained using single-spore technique (Leslie and Summerell. 2006), and the isolation rate was 75%. The isolates grew rapidly on PDA, produced large numbers of fluffy white hyphae, and pink pigment accumulated in the medium. The isolates were grown on 2% mung bean flour medium and identified by morphological and molecular methods. Macroconidia were abundant, relatively slender, curved to almost straight, commonly two to seven septate, and averaged 22 to 72 × 1.8 to 4.9 µm. Microconidia were not observed. The morphological characters are consistent with Fusarium (Aoki and O'Donnell. 1999). Two isolates (LP-1 and LP-3) were selected for molecular identification. Primers EF1/EF2 (5'-ATGGGTAAGGARGACAAGAC-3'/5'-GGARGTACCAGTSATCATG-3') were used to amplify a portion of the EF-1α gene (O'Donnell et al. 1998). The two 696 bp PCR products were sequenced and submitted to GenBank. The EF-1α gene sequences (GenBank Accession No: PP062794 and PP062795) shared 99.9% identity (695/696) with published F.pseudograminearum sequences (e.g., OP105187, OP105184, OP105179, OP105173). The identification was further confirmed by F. pseudograminearum species-specific PCR primers Fp1-1/Fp1-2 (Aoki and O'Donnell. 1999). The expected PCR products of 518 bp were produced only in F. pseudograminearum. Pathogenicity tests of LP-1 and LP-3 isolates were performed on 7-day-old seedlings of winter wheat cv. Xindong 20 using the drip inoculation method with a 10-µl of a 106 macroconidia ml-1 suspension near the stem base (Xu et al. 2017). The experiment was repeated five times in a 20 to 25°C greenhouse. Control seedlings were treated with sterile water. After 4 weeks, wheat seedling death and crown browning occurred in the inoculated plants with over 90% incidence. No symptoms were observed in the control plants. The pathogen was reisolated from the inoculated plants by the method described above and identified by morphological and PCR amplification using F. pseudograminearum species-specific primers Fp1-1/Fp1-2. No F. pseudograminearum was isolated from the control plants, fulfilling Koch's postulates. To our knowledge, this is the first report of F. pseudograminearum causing crown rot of winter wheat in XUAR of China. Since F. pseudograminearum can cause great damage to wheat, one of the most important food crops in China, necessary measures should be taken to prevent the spread of F. pseudograminearum to other regions.

Multi-generational Effects of Different Resistant Wheat Varieties on Fitness of Sitobion avenae (Hemiptera: Aphididae).

Crop resistance plays a role in preventing aphid damage, benefiting food production industries, but its effects are limited due to aphid adaptation and phenotypic plasticity. Therefore, furthering understanding of aphid-crop interactions will improve our ability to protect crops from aphids. To determine how aphids adapt to resistant varieties of wheat, Triticum aestivum L. over time, we performed a laboratory experiment to assess the multi-generational effects of three wheat varieties, Batis, Ww2730, and Xiaoyan22, with different resistance levels on the fitness of Sitobion avenae (Fab.) (Hemiptera: Aphididae). The results showed that Ww2730 and Xiaoyan22 were more resistant than Batis to S. avenae, regardless of whether the aphids were newly introduced or had been acclimated before being introduced to the three wheat varieties. However, the effect of resistance on aphid life-history traits was time dependent. Aphid weigh gain increased and they development faster of the acclimated generation compared to the newly introduced generation on all three varieties. And the fecundity on the three varieties and net reproduction rates on Batis and Xiaoyan22 significantly decreased. Aphid fitness in terms of individual life-history parameters improved, whereas aphid fitness in terms of reproductive decreased, and a convergence effect, the difference gaps and standard errors of all life-history traits among the three acclimated populations had narrowed and were less than those in the three first-generation populations, was observed during the 3-mo experimental period. We suggested that S. avenae could rapidly respond to wheat resistance through life-history plasticity.

A meta-analysis: The diagnostic values of long non-coding RNA as a biomarker for gastric cancer.

Long non-coding RNAs (lncRNAs) have been identified as novel biomarkers for the diagnosis, staging and prognosis for gastric cancer. However, various studies have reported a series of significances based on different diagnostic values. Therefore, the current study performed a systematic review and meta-analysis to evaluate the diagnostic accuracy of lncRNAs for gastric cancer, and to discuss lncRNA types and sources of heterogeneity. The Cochrane Central Register of Controlled Trials, MEDLINE, PubMed, EMBASE, the Chinese Biomedical Literature Database, the China Academic Journals Full-text Database and the Chinese Scientific Journals Database were systematically searched for potential studies. Studies were included if they were associated with lncRNAs, gastric cancer and reported diagnostic outcomes. Analysis of diagnostic values was used to summarize the overall test performance of lncRNAs. Ten studies were included in this meta-analysis. The ranges of the diagnostic value of lncRNAs for gastric cancer were as follows: Sensitivity was 0.45-0.83, and pooled sensitivity was 0.63; specificity was 0.60-0.93, and pooled specificity was 0.75; positive likelihood ratio was 1.80-6.92, and pooled positive likelihood ratio was 2.51; negative likelihood ratio was 0.23-0.67, and pooled negative likelihood ratio was 0.50; diagnostic odds ratio was 3.33-13.75, and pooled diagnostic odds ratio was 5.47. An overall area under the curve value of the summary receiver operating characteristic curve was 0.7550. LncRNAs did not have a high accuracy for identifying gastric cancer at present, but may be a useful screening tool for diagnosing gastric cancer due to their correlation with gastric cancer biological features. LncRNAs are potential biomarkers for gastric cancer if the screening strategy is altered, or they are combined with other biomarkers to diagnose gastric cancer.

[Impact of secondary pancreatic infection on the prognosis of patients with severe acute pancreatitis: an analysis of 60 cases].

OBJECTIVE: To investigate the impact of secondary pancreatic infection (SPI) on the prognosis of patients with severe acute pancreatitis (SAP). METHODS: Clinical data of 60 patients with SAP (January 1, 1980-December 31, 1999), especially the data at the onset of SPI, were retrospectively analyzed. RESULTS: Sixty patients were divided into two groups: SPI group (29 cases) and non-SPI group (31 cases). There was no significant difference in gender, average age, scores of Ranson and of high risk factors of China Medical Association between two groups, but the average stay days in hospital, payment, acute physiology and chronic health evaluation II (APACHE II) scores, days of fever, prehospital days, days of high white blood cell (WBC) count, the duration of constipation after the onset of SAP and average times of operation were significantly higher in SPI group than that of non-SPI group. Fatality rate of SPI group (7/29, 24.14 percent) was higher than that of non-SPI (1/31, 3.23 percent). There were 14 cases of infection with single microorganism (48.3 percent) and 15 cases of mixed infection (51.7 percent) in SPI group. Twenty-seven patients were infected with bacteria of Enterobacteriaecae (Escherichia 25, Klebsiella pneumoniae 1, Proteus morgani 1, 8 with bacteria of Pseudomonas (P. aeruginosa 7, P. stanieri 1), 2 with fungus, 5 with other bacteria (Bacillus subtilis 2, Tetracoccus 1, Acetobacteraceae 1, Staphylococcus epidermidis 1) in SPI group. Only in 2 patients with infective pancreatic necrosis the blood culture was positive (Escherichia coli). CONCLUSION: These results showed that the major source of SPI is entergenous, and SPI would affect the prognosis of SAP patients. With the present therapeutic regimes it was hard to prevent entergenous infections. It is necessary to find a new strategy.